If an American Household Were Chosen at Random and Asked

Multiple Choice

If an American household were chosen at random and asked how many tablet computers it owned, here are the probabilities as determined by a recent survey:

This is a legitimate assignment of probabilities because it satisfies these rules:

A) all the probabilities are between 0 and 1.
B) all the probabilities are between -1 and 1.
C) the sum of all the probabilities is exactly 1.
D) All the probabilities are between 0 and 1, and the sum of all the probabilities is exactly 1.
E) All the probabilities are between -1 and 1, and the sum of all the probabilities is exactly 1..